Validity and Reliability of the Kazakh Version of the Health-related Quality of Life Questionnaire for Gastroesophageal Reflux Disease

A BSTRACT Gastroesophageal reflux disease (GERD) is a multifactorial condition that significantly impacts patients’ quality of life. To standardize the assessment of symptoms and their effect on daily activities, specialized questionnaires are widely used. One of the most commonly employed tools is the GERD–Health-related Quality of Life (GERD-HRQL) questionnaire. Despite its widespread use in international practice, a Kazakh-language version of this instrument has not been available until now. To adapt the GERD-HRQL questionnaire into the Kazakh language and assess its validity and reliability for use in clinical practice and research in the Republic of Kazakhstan. The study was conducted at the M. Ospanov West Kazakhstan Medical University from January to September 2025. The study included patients with GERD symptoms without alarm signs. The adaptation process involved forward and backward translation, expert evaluation, cognitive debriefing, and statistical testing of reliability (test–retest and Cronbach’s alpha coefficient) and validity of the instrument. The original 11-item version of the GERD-HRQL questionnaire, supplemented with a modified section on regurgitation symptoms, was used as the source material. The Kazakh version of the GERD-HRQL questionnaire demonstrated a satisfactory level of internal consistency (α = 0.951) and reproducibility upon retesting ( r = 0.898). High scores were noted for clarity, readability, and ease of use. Content and face validity were confirmed by both patients and healthcare professionals. The Kazakh version of the GERD-HRQL questionnaire is a valid and reliable instrument for assessing GERD symptoms and patients’ quality of life. It can be effectively used in clinical practice and scientific research, including monitoring the effectiveness of therapy and surgical interventions. In addition, it supports the implementation of a patient-centered approach in gastroenterological practice in Kazakhstan.